U.S. Focus on ISIS Frees Syria to Battle Rebels

BEIRUT, Lebanon — As American warplanes cross the Syrian sky dropping bombs on Islamic State militants, another set of air raids has sown destruction across the country, as the Syrian government returns with new intensity to its longstanding and systematic attacks on rebellious towns and neighborhoods.

On Saturday, a mushroom cloud towered over the town of Saraqeb in the northern province of Idlib, after a ground-shaking government bombing that residents said killed two civilians and wounded six.

On Sept. 26, government warplanes struck the nearby town of Bdama, injuring 11 people, damaging a school and enraging residents who initially assumed the planes were American.

And in the northern province of Aleppo, army helicopters have been dropping crude barrel bombs packed with explosives on a near-daily basis, sending residents to dig the dead and wounded from the rubble with their bare hands. Dozens have died in such bombings since the American-led air campaign began.

Such attacks — from airspace that American warplanes now enter at will — have fueled anger at the United States among opponents of President Bashar al-Assad of Syria, who wonder why the Americans are leading the fight against the Islamic State but give free hand to a dictator whose fight to remain in power has left as many as 200,000 of his own people dead.

The United States’ focus on the Islamic State has given cover to Syrian forces, they say. That has freed Mr. Assad’s military from worrying about checking the militant group’s advances and allowed them to continue to focus attacks on the greater political threat — less extreme Syrian-based insurgent groups bent on ousting Mr. Assad and the communities where they hold sway.

The Syrian government had long focused its attacks on insurgents other than the Islamic State, a group that had seemed more interested in establishing Islamic rule in its territories than in ousting Mr. Assad. But after the group overran parts of Iraq and carried out a series of lightning routs of Syrian Army bases, terrifying many government supporters, Syrian warplanes began attacking it with more intensity in its eastern strongholds.

Since the American-led campaign began about two weeks ago, however, the need for Syrian forces to check the Islamic State has ebbed, and some insurgents who oppose the militant group say the government attacks on them have intensified.

A United States official said there were indications that since the American campaign started, Syrian fighter jets and helicopters had increased strikes somewhat in the core territories of non-Islamic State insurgents, such as Idlib, Aleppo and the Damascus suburbs.

“It would be silly for them not to take advantage of the U.S. doing airstrikes,” said the official, who spoke on condition of anonymity to discuss confidential intelligence reports. “They’ve focused in the west and left off the east, where we are operating. Essentially, we’ve allowed them to perform an economy of force. They don’t have to be focused all over the country, just on those who threaten their population centers.”

That dynamic is at the heart of Washington’s impasse with President Recep Tayyip Erdogan of Turkey, who is demanding that President Obama increase efforts to oust Mr. Assad before Turkey takes tougher action against the Islamic State.

The attacks by the Syrian government are creating other political problems for the United States. With both air forces in the sky, attacks by the Syrian government can be mistaken for American ones, including raids that kill civilians.

Mistrust of the United States is deepening among Syrian opponents of the government, including insurgents whom Mr. Obama hopes to train as a ground force against Islamic State militants.

“Syria is divided between Assad and the coalition,” said Suhail, a fighter with the Free Syrian Army, the loose-knit group from whose ranks the United States is vetting potential allies. “The Syrian citizen is paying the price. The coalition took some of the burden from the regime.”

Some Syrians go further, saying that the simultaneous bombings are evidence that the United States is covertly coordinating with the Syrian government. Mr. Obama has publicly ruled out such coordination, saying Mr. Assad lost his legitimacy after using force against peaceful protesters and carrying out indiscriminate bombings.

“From a military perspective — there’s no communication or coordination with the Assad regime,” said Rear Adm. John Kirby, the Pentagon press secretary, adding that American strikes were focused in “largely ungoverned spaces that he long ago lost any control over.”

American pilots are under orders to avoid any contact with Syrian warplanes, military officials said, and, using navigational instruments and data from allied aircraft, do not need to communicate with them to avert collisions.

That nuance, though, is lost on Syrians who feel abandoned by the world, and see Washington’s decision to prioritize the battle against the Islamic State as a victory for Mr. Assad’s strategy of eliminating moderate opposition and presenting his international opponents with a choice between him and extremists.

“Our protection as civilians and as minorities is not on the coalition’s political agenda” said Nadeen, a Syrian Christian who opposes the government and lives in the government-held section of divided Aleppo. “Nor is fighting the regime.”

Asking that only her first name be used for her safety, she added, “If they are serious about arming the opposition, they would not allow Assad to eliminate rebels and civilians.”

At the same time, the campaign against the Islamic State faces challenges of its own in Kobani, the Syrian Kurdish enclave on the brink of falling to the militants. American-led airstrikes grew more frequent on Tuesday and Wednesday amid an outcry over the coalition’s failure to stop the assault. But the bombardment did not prevent Islamic State militants from moving north, deeper into the town and closer to the Turkish border, said a Kurdish official, Assi Abdullah.

Confusion has been deepened by the American decision to strike what it said was a Qaeda cell called the Khorassan Group in Idlib province, in territory held by non-Islamic State insurgents. Further complicating matters, local insurgents and residents knew the fighters targeted in that attack simply as members of the Nusra Front, the Qaeda affiliate in Syria that is viewed as an ally, at least tactically, by many rebel groups, including some nominally allied with the West.

That helped lead Syrians to believe that the United States was targeting the insurgency writ large, and that later government airstrikes in the area were carried out by the United States.

The Bdama strike was a case in point. Sasha Ghosh-Siminoff, an American aid worker who worked there, said his contacts were convinced that the Americans had hit them, even though insurgents there oppose the Islamic State and some work closely with the Americans.

Residents of Idlib and Aleppo now say, “We don’t know who’s hitting us,” Mr. Ghosh-Siminoff said from Washington, where he runs an aid group called People Demand Change.

Even after word came that the strike was conducted by Syrian planes, he said: “It brings up the question, ‘Does the American government have a deal with the Assad regime about flying their air force?’ Which is more damaging? I would almost prefer it to be an American airstrike that hit by mistake — they could apologize and move on.”

A version of this article appears in print on , on Page A12 of the New York edition with the headline: American Focus on Islamic State Frees Syria to Battle Rebels. Order Reprints | Today’s Paper | Subscribe